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Content:Introduction

 Elevatorterminology andcomponentsTypes of elevators

Safety features

Types ofEmergencies

2

` There are two types of Elevators:- a xydraulic a Rope-GearedThe hydraulic elevator consists of a cabattached to the top of a hydraulic jack similarto a jack used for a car lift in a servicestation. The hydraulic jack assembly normallyextends below the lowest floor and isoperated by a hydraulic pump and reservoir,both of which are usually located in aseparate room adjacent to the elevator shaft,xydraulic elevators are the type generallyused in single-family residencesxydraulicFound in two types:Plunger type and Roped hydraulic

½xydraulic - Plunger typeThis type is the most common and consists ofan elevator car mounted on top of a longhydraulic piston. The piston is generally nottelescopic, so there must be a hole in theground as long as the distance the elevatortravels.

The Otis Roped xydraulic has aplunger (A) located on each sideof the car and a sheave (B)controlled by a set of plungerguides (C). Ropes (D) arefastened to the top of jack stands(E) and the bottom of the carframe. The system has aninstantaneous safety (F) that isactivated by a traction governor(G) and governor tension sheave(x).xydraulic ± Roped hydraulic

2` Two Disadvantages a £ust xave Enough Room a Energy Inefficient` These are the most popular types of elevators.` Rather than being pushed from below, these types of elevators are moved using cables` Rails are used to guide the elevator` Keep elevator and counterweights steady.` Rope-geared elevators are much more efficient and safer.uELEVATOR CARuxOISTWAYu£ACxINE /DRIVE SYSTE£uCONTROL SYSTE£uSAFETY SYSTE£Elevator carThe elevator car door travels through thehoistway with the car.A toe guard is present at the bottom of somecars. This guard protects the passengersfrom being exposed to the open hoistwayunder the car if the doors are opened when itis not at the landing. The guard is between2 and 4ë long.

ëCross head

Safety plank

2Elevator car-contd.The elevator car door travels through thehoistway with the car.A toe guard is present at the bottom of somecars. This guard protects the passengersfrom being exposed to the open hoistwayunder the car if the doors are opened when itis not at the landing. The guard is between2 and 4ë long.

2 22Complements of The American Society of £echanicalEngineers xoistway

The shaft that encompasses the elevator car.

Generally serving all floors of the building.

23In high-rise buildings hoistways may be banked. Withspecific hoistways serving only the lower floors andothers serving only middle or upper floors whiletraveling in a blind hoistway until reaching the floorsthat it serves. A blind hoistway has no doors on thefloors that it does not serve.25262½xorizontal operating hoistway doors are generallyhung from the top on rollers that run in a track,with the bottom of the door running in a slot.Forcing these doors at the middle or at the bottom willcause damage to the doors and their mountinghardware. The doors can also be knocked out of theirtrack and fall into the hoistway` The hoistway door locking mechanism provides a means to mechanically lock each hoistway door. They are also interconnected electrically to prevent operation of the elevator if any of the elevator¶s hoistway doors are open.xoistway doorinterlockInterlock for freightelevator

33Carried on trucks and the squad, permit the unlocking ofthe hoistway door interlock.The keyhole on the upper portion of a hoistway door thataccepts a hoistway emergency door key and permitsunlocking of the hoistway door locking mechanism.

These keyholes are usually located at the bottom and top

floors, but may also be on other selected floors or all floorsEscutcheon tube

3½Escutcheon tubePhoto-electric and infraredsensorsA sensor between the hoistway and car doorsthat detects objects in their path and preventsthe doors from closing.Photo-electric eyes were problematic and arebeing phased out.

3Infra-red sensor

4Roller guidesA set of three wheels that roll against the guiderails.

Usually mounted to the safety plank and

crosshead. They keep the car in contact withthe guide rails and prevent sway.

4Roller guidesonCross head

42Roller guideson Safetyplank

43SafetiesEmergency braking mechanism that stops thecar by wedging into the guide rails when overspeeding has occurred.

It is activated by the speed governor sensing

over speeding of the elevator car.

44Safeties

45Safeties

Governor rope

46xoisting cables (or ropes)Used on traction type elevators, usuallyattached to the crosshead and extending up intothe machine room looping over the sheave onthe motor and then down to the counter weights.

xoisting cable are generally 3 to 6 in number.

They are steel with a hemp core to keep thempliable and lubricated. 4½xoisting cables (or ropes)These cables are usually /2or 5/ë in diameter.The /2cables have a breaking strength of4,5 lbs and the 5/ë 23, lbs each.

xowever, at degrees the wire steel rope

contains only about 3% of its original tensilestrength.

4ëNickel Babbitt

4xoistingcables

Wedge clamp

55Guide railsTracks in the form of a ³T that run the length ofthe hoistway, that guide the elevator car.

Usually mounted to the sides of the hoistway, at

the middle of the elevator car.

52Guide rail Guide rail

53Governor sheaveProvided to detect over speeding of the car.Usually a cable is attached to the safeties on theunder side of the car, called the governor rope.This rope runs down through a pulley at thebottom of the shaft and back up to the machineroom and around the governor sheave.

When over-speeding is detected, the governor

grips the cable which applies the safeties thatwedge against the guide rails and stops the car. 54Governorsheave

55Governorrope

56Governorrope

5½Car emergency exitUsually located at the top of the elevator cars,sometimes on the side, other times not present.

Top exits open from outside the car.

Side exits are extremely dangerous to use andare no longer being installed. Existing side exitshave been disabled by being permanentlybolted shut.

5ëTopemergencyexit

5£achine roomFor hydraulic plunger typeUsually located in the basement or first floor, butcould be anywhere.

Generally containing the electric motors, pumps,

oil reservoirs, controllers and electricaldisconnect to the elevators.

66` £ore ropes than needed` Built-in brake systems` Governor prevents the elevator from falling to the bottom of the shaft. Centrifugal force causes a brake system to activate.` Also has an electromagnetic brake that is activated if the elevator loses power.` Automated Brake System at the top and bottom of the shaft.Safety featuresSafeties ± a stopping mechanism for an overspeeding car.

Interlocks ± Cuts power to the car if this

electrical/mechanical interconnection is broken.

Emergency stop switch ± The red switch inside

some cars that cuts off the power to the carexcept for the lights, alarm and communicationsystem. 64Safety featuresSeismic switch - A motion sensing device onsome elevators installations. If it is activated theelevator will move away from the counterweights to the next landing with its doors openand inoperable.This device overrides phase I and phase IIoperation unless phase II operation is already ineffect.

65Safety featuresIf this device has been activated it can meanthat an unsafe structural condition exists.

This device is located in the machine room.

666½Safety featuresSeismic valve for hydraulic elevators - A valvelocated in the pit close to the jack that isdesigned to hold pressure if the hydraulic line isbroken due to seismic activity.

6ëSeismic valve

6Elevator emergenciesIn many cases an elevator technician cancorrect a problem faster than we can initiate arescue.Elevator technicians are on call 24hrs a day andcan usually respond within an hour.When dispatched on a elevator emergency,verify that an elevator technician has beennotified.

½Types of emergenciesPerson trapped in elevator car

The 3 most common reasons:

± Power failure± £alfunction of control components± Activation of safety equipment

½- Power failure

If it¶s going to be short term, its best not to

attempt a rescue. Explain the situation to theoccupant. Calm and reassure them and letthem know that they are not in danger and stepsare being taken to remove them safely.

If emergency power is available, it can be used.

½2- Power failure

Some newer elevators will return to the lobby

one at a time where the doors will openautomatically.

½3- £alfunction of control components

Shut off the power to the elevator in the machine

room.This will prevent any unexpected movement ofthe car when the power is restored.

½4- Activation of safety equipment.If one of the elevator¶s safety devices has beenactivated, it is often indicating a seriousmalfunction in the hoistway or operatingmachinery.

½5- Activation of safety equipment.In this situation we should wait for an elevatortechnician. Leave the power on to the elevator.This will help the technician in determining theproblem.xowever, if we have to perform a rescue, turnoff the main power to the elevator in themachine room.